1. Field of the Invention
The present invention relates to a light-emitting device and a method for manufacturing the light-emitting device.
2. Description of the Related Art
A light-emitting diode (LED) using gallium nitride has been developed actively and has been increasingly practically used for a lighting device or the like.
Characteristics of a light-emitting device, such as emission efficiency and durability life, are greatly affected by the crystal quality of a light-emitting layer. As a substrate included in a light-emitting device, an inexpensive sapphire substrate or the like is often used; however, the crystal quality of a light-emitting layer depends on a substrate where the light-emitting layer is formed. Therefore, a gallium nitride single crystal substrate has been researched as a substrate for a light-emitting device with which a light-emitting layer having favorable crystal quality is obtained (for example, see Patent Document 1).
Further, a gallium-nitride-based light-emitting diode which uses a gallium oxide substrate whose main surface is formed of single crystal gallium oxide has been also researched and developed (for example, see Patent Document 2).